1. Field of the Invention
The present invention relates to air conditioners, and more particularly, to an air conditioner which can delay growth of frost on an outdoor heat exchanger, and a method for controlling an operation of the same.
2. Background of the Related Art
In general, the air conditioner cools or heats a room space, such as a residential space, a restaurant, and an office.
The air conditioner in general is provided with an indoor unit and an outdoor unit. The outdoor unit has a compressor, an outdoor heat exchanger, and an accumulator, and the indoor unit has an indoor heat exchanger, and an expansion valve.
When the air conditioner cools a room, the refrigerant flows in an order of the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger.
The outdoor heat exchanger serves as a condenser for condensing the high pressure, high temperature gas refrigerant from the compressor. The expansion valve 22 expands the condensed refrigerant into low pressure, low pressure gas refrigerant, and provides to the indoor heat exchanger.
The indoor heat exchanger 21 makes the refrigerant to heat changes with room air to change the refrigerant into two phased refrigerant having low temperature/low pressure gas and liquid refrigerant mixed therein.
On the other hand, when the air conditioner heats the room, the refrigerant compressed at the compressor flows in an order of the indoor heat exchanger, the expansion valve, the accumulator, and the outdoor heat exchanger.
In this instance, the indoor heat exchanger serves as a condenser for making the high pressure, high temperature refrigerant passed through an inside of the indoor heat exchanger to heat exchange with room air, and the outdoor heat exchanger serves as an evaporator for making the low temperature, low pressure refrigerant therein to heat exchange with an outdoor air.
The accumulator serves to prevent introduction of liquid refrigerant into the compressor, only to introduce gas refrigerant into the compressor.
In the meantime, in the heating operation of the air conditioner, it is liable that the heat exchange of the outdoor heat exchanger with surrounding low temperature humid air causes growth of frost on the outdoor heat exchanger. The frost makes the heat exchange of the outdoor heat exchanger with the outdoor air difficult. Therefore, a defrosting operation is carried out, in which refrigerant flow is reversed for removal of the frost.
In the defrosting operation, the refrigerant flows in an order of the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger. When the defrosting operation is finished, the heating is started, again.
Thus, the related art air conditioner carries out the defrosting operation in which refrigerant flow is reversed for prevention of growth of frost on the outdoor heat exchanger.
However, the more frequent the defrosting operation, the poorer the operation ratio of the air conditioner, that leads to a poor heating efficiency.